Epidemiology and Pathogenesis of Ulcerative Colitis.

Ulcerative colitis (UC) is a complex chronic, immune-mediated inflammatory disorder of the colon. Factors associated with increased risk of UC include diet, particularly Western diet influences in newly industrialized nations, medications, and lifestyle factors that may influence the host's microbiome or immune response to antigens. Although much evidence identifying potential genetic and host-related factors is currently available, there are still many unanswered questions. As the global UC incidence and prevalence continues to increase, there are multiple opportunities for continued investigation to clarify our understanding of UC, identify potential predictors of disease severity, response to therapy, and novel therapeutic targets.